INTERVIEWS

In an attempt to gain a broader perspective about back pain and its relationship with incorrect posture, as well as an insight into what other people might want in an ‘Easy Kneeling Chair’; I have interviewed a number of people who have back problems.

THE INTERVIEW OUTLINE

DETAIL OF TYPE OF BACK PAIN:

  • If you have back pain, where does it physically hurt?
  • Is it related to a particular situation or injury?
  • Have you been advised to do anything to alleviate it and by whom?

KNEELING CHAIR:

  • Have you used a kneeling chair before?
  • How was the experience?
  • Could it be improved for you in any way?
  • Have you used any other device to try to alleviate back pain whilst seated?

PROPOSED PROJECT:

  • I propose to design a chair using the same principles to correctly align the spine as the kneeling chair, but as an easy chair rather than an office chair. Do you think that would be of interest to you?

Thinking about such a chair;

  • What would aesthetically convey a sense of comfort and relaxation to you?
  • Are there other practical or aesthetic issues you feel it would need to address?
  • What type of style of chair would you like?
    Modern, Contemporary or Traditional? Lightweight, Sculptural or Solid?

The results can be seen under the ‘INTERVIEW’ tab.

Please feel free to complete the survey too (whether you have back pain or not) and leave your response either as a comment here or under the INTERVIEW tab.

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THE EASY KNEELER

Galen Cranz in her book ‘The Chair’ describes a short survey she had students complete once in 1984 and again in 1994, whilst sat in a kneeling chair (a cheap Balans style chair with no rockers). Although most of the students recognised what type of chair it was, 36% had never sat in one, and some needed instruction on how to actually sit on it. Some of the results are detailed below.

Why do you think it is shaped the way it is?

Over 75% perceived that it was the designers’ intention to promote greater health and comfort.

Are you comfortable now in the Chair?

77% said YES.

Does the chair seem to fit your body size and proportions?

89% said YES.

Are there any points where your contact with the chair causes discomfort?

60% said NO. Comments made about discomfort were mostly about pressure on the knees and legs.

She also asked questions about their attitude to the chair and where they might use it. Despite the vast majority of participants finding the chair comfortable, it was clear that the chair had been socially and psychologically categorised as a work or computer chair. Cranz suggest that this is because the design was essentially utilitarian and doesn’t communicate enough about style and image.

One wonders whether she would have received similar results if she had used the much more stylish Gravity Chair instead.

Cranz G., 2000. The Chair; Rethinking Culture, Body and Design. New York: W. W. Norton & Company.

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DESIGN CRITERIA FOR KNEELING CHAIRS

  • There is no need for back support because the aim is to sit autonomously.
  • The seat should slope forward to open up the angle between torso and thigh to maintain the natural S-shaped curve of the back.
  • Weight is born on Sit Bones (Ischial Tuberosity) and the Shins.
  • Typically the angle of slope of the seat would be approximately 15o.
  • The steeper the angle of slope, the more the body will tend to slip forward, putting more pressure on the shins.
  • The seat can be less deep than traditional chair seats, because the thigh is not bearing any weight.
  • The seat and knee pads should be flat or slightly convex (curved downwards), so the edge does not cut into or compress the flesh in any way.
  • Padding is required for comfort on both seat and knee pad.
  • Padding should not be too thick, ¼ to ½ inch firm foam or wool felt is appropriate.
  • The position of the knee pad relative to the seat should allow the thighs to drop downwards to allow the pelvic angle to open and the spine stay effortlessly in correct alignment.
  • Flexing the knee relaxes the hamstring muscle and reduces the tendency for the spine to form the C-shaped slump.
  • The knee pad should slope backwards, to create a relaxed kneeling-like position.
  • The height of the chair can be altered to the environment because the legs are tucked into a kneeling position, rather than having to be placed flat on the floor.
  • The distance between seat and knee pad should take into account the length of the thigh bone. (This bone actually shows a high degree of similarity in length across the population.)
  • It is the shin that should rest on the knee pad and bear weight, not the knee.
  • The ankles and feet bear no weight and should be free to move and rotate.
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REQUIREMENTS OF THE SEATED FORM

FIRM AND SOFT:

When sitting, weight should be distributed through bone not flesh. Seated with a correctly aligned posture your weight should be bearing on your Ischial Tuberosity (Sit Bones). For comfort some sort of cushioning is preferred, but you should still be able to feel the counter pressure of the underlying structure to maintain postural stability. Approximately ¼ to ½ inch firm foam or wool felt is appropriate for this. If the padding is too thick, the body cannot feel the underlying structure and therefore tends to collapse in on itself. In this situation the surrounding tissue gets compressed because it too has to bear weight. This pressure reduces blood circulation.

STABILITY AND MOVEMENT:

As human beings we are in a constant state of movement, it is unnatural for us to be perfectly still. A balance therefore needs to be found between the physical need to move and the requirements to be still enough to complete a task. Many ergonomically designed chairs try to cradle the body in a fixed position rather than let the body sit autonomously. Galen Cranz in her book ‘The Chair’ suggests that flat or planar surfaces that do not constrict movement would be better than these overly constrictive curved forms. When sitting autonomously you strengthen your core muscles which improves your posture when sitting and standing and reduces back pain and the possibility of further injury.

Cranz G., 2000. The Chair; Rethinking Culture, Body and Design. New York: W. W. Norton & Company.

Gibbs N., ed., 1990. The Woodworker book of Joinery. Wiltshire: Argus Books

 

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THE KNEELING SEAT

Kneeling on hard or uneven ground can be very uncomfortable for the knees, shins and ankles, particularly if you sink back onto your haunches. Kneeling therefore really requires a soft surface beneath, such as rugs, carpets, or cushions, and perhaps something to help support your bottom so that you do not end up sat on your ankle bones.

A traditional Seiza Bench on padded mat.

Meditation requires that you empty your mind and be free of all external and internal distractions. Sitting in meditation is traditionally done in a crossed-legged Burmese/Lotus position or a kneeling position, because these poses allow the back to be in correct alignment and the meditator to be less distracted by physical discomfort.

The ‘Seiza’ Bench has been used by Buddhist monks in Tibet and Japan for centuries for this reason. It creates a kneeling-like position that can be maintained in comfort for extended periods. The weight of the torso is lifted off the ankles and shins, and the forward tilting seat opens up the angle between trunk and thighs putting the back into its correct S-shaped alignment.

An alternative Seiza Bench Design.

An alternative is the traditional ‘Zafu’ Cushion. This can be used for both crossed legged or kneeling positions. For kneeling the rounded cushion lifts the pelvis again opening up the angle between torso and thighs and aligning the spine. It is interesting to note that the full lotus position physically forces the thighs downwards thereby achieving this same objective.

A Zafu Cushion

In recent decades a number of chair designs have developed this kneeling-like sitting position based on the research by Dr. A. C. Mandal’s that concluded that a forward sloping seat did effectively tipped the pelvis forward opening up the angle between torso and thigh and thereby correctly align the spine. A sample of which are shown below:

Primate Achille Castiglioni: 1970

This seat allows a number of different positions, from standard seating, kneeling and reversed draped over the seat.

Buzzi: 1970

J. Harding Vowles: 1972

Peter Gillings Jnr: 1973 (Originally designed for a snow mobile seat.)

Hans C Mengshoel: 1979

Balans Chair: Hans C. Mengshoel, Svein Gusrud & Peter Opsvik: 1979

Dropping the legs, so your thighs are at an oblique angle to the torso of between 120o and 135o solves the problem of stress in the lower back that is associated with traditional 90o sitting position. In this position the musclular work of sitting upright is evenly balanced between front and back, so it feels almost effortless. The rockers allow movement whilst in this position and aid in the building of core strength.

Gravity Chair: Peter Opsvik:

This was developed from the Balans chair and transforms from lounger, to conventional chair to kneeling chair as it rocks forward.

X-shaped Frame Kneeling Chair:

This style developed to increase stability and allow adaptability in heights and angles. The one pictured here has a screw mechanism to allow continuous adjustment. Manoeuvrability  is enhanced with castors.

I have previously owned a chair like this and found that the rear base junction is weak, particularly if someone perches on the chair in reverse!

5-Star Base Kneeling Chair:

The kneeling chair has become synonymous with office work in the past few years, so it is unsurprising that it is being styled like other office chairs. This base is stable but allows for mobility when seated. You can lean forwards and backwards, twist around, or stretch one or both legs out from the kneeling position and propel yourself on the castors to reach objects, all whilst being in a position that allows you to sit comfortably and autonomously. Some such chairs are sold with backs to make them appear more traditional, but backs are completely superfluous, you do not need or use them!

Cranz G., 2000. The Chair; Rethinking Culture, Body and Design. New York: W. W. Norton & Company.

Gibbs N., ed., 1990. The Woodworker book of Joinery. Wiltshire: Argus Books

http://www.kneelingchair.com.au

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PERCHING AND KNEELING

It was found through the studies of Mandal and others, that the natural S-shaped curve of the spine could be more easily maintained by sloping the chair seat forward thereby opening up the angle between torso and thighs and/or flexing the knees to relax the hamstring muscle.

This resulted in two ideas: perching and kneeling both of which give the benefits previously discussed.

PERCHING

Mandal himself preferred the idea of perching, a position half way between sitting and standing.

The critical issue for him was opening up the angle between torso and thigh. This resulted in a chair that had a curved seat the front of which was forward sloping at an angle of approx. 15o. Stability is achieved by perching on the edge of the seat, forming a tripod between the seat bones and the feet. Because the thighs sloped downwards to open up the pelvic angle and the feet had to be firmly planted on the floor, the chair necessarily had to be higher than normal. This design was taken up by schools in Denmark, France and Scandinavia and functions well, but necessitates the redesign of desks to accommodate the increased height.

Mandal recognised that maintaining this position would be tiring in the long run, so the rear of the chair is more traditional, with a flatter seat and backrest, so pupils could revert to a sitting position to ‘rest’, stretch their legs out and put their feet up on a bar under the desk.

PROBLEM 1:

Raising the seating height necessitates the redesign of the entire environment.

PROBLEM 2:

The position is tiring because much of your weight is still on your legs and feet.

PROBLEM 3:

The ankles are still flexed giving rise to problems associated with varicose veins.

PROBLEM 4:

The need to maintain stability makes this position fairly static.

KNEELING

Another way to achieve correct spinal alignment is through a kneeling-like position. This both opens the pelvic angle and flexes the knee to relax the hamstring muscle.

The Balans is probably the most well-known example of this type of chair. The seat is sloped forward at approx. 15o to open up the angle between torso and thighs. The majority of the body’s weight is transferred through the sit bones but to provide stability and to arrest any tendency to slip forward, the legs are bent at the knee and the shins rest lightly on a lower backward sloping ‘Knee Pad’.

It is worth noting that it is the shin not the knee that rests on this pad, because some have claimed this type of kneeling chair puts pressure on the knee. I can personally attest that this is not necessarily the case, having smashed my kneecap a number of years ago, I have had no pain or problems with using a kneeling chair. However it is generally not advised for anyone with knee problems.

Because the legs are bent and the feet are not planted on the floor, the chair can easily accommodate various leg lengths. The feet and ankles themselves bear no weight and are free to move and relax. Despite claims to the contrary, the position is not static, it is quite easy to slip one or both legs off the knee pad to shift position, whilst still easily maintaining a relaxed upright posture.

Initially you may have to be shown how to use one, however once you have learnt how to do so, unless you have serious mobility problems sitting and standing is actually easier than in a normal chair because your spine is already in the correct alignment.

PROBLEM 1:

Initially you may have to be shown how to use one!

PROBLEM 2:

Not advised for people with poor leg circulation or knee problems.

On considerations of the problems associated with kneeling and perching, I consider ‘kneeling’ to be a better option for relaxed seating.

Cranz G., 2000. The Chair; Rethinking Culture, Body and Design. New York: W. W. Norton & Company.

Gibbs N., ed., 1990. The Woodworker book of Joinery. Wiltshire: Argus Books

http://www.kneelingchairs.com.au

 

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THE BENEFITS OF CORRECT SPINAL ALIGNMENT

When we sit with the spine correctly aligned in its proper S-shaped curve, the muscles needed to maintain the upright body are equally balanced at both front and back, so the position feels effortless. It can also have numerous other health benefits.

  • Allows effortless ‘Autonomous Sitting’ (sitting without the need of back support).
  • Reduces Muscle Tension and Strain.
  • Increases Core Strength.
  • Improves Posture both Sitting and Standing.
  • Elongates the Spine
  • Repositions the Shoulders
  • Opens up the Chest.
  • Reduces Pressure on all the Internal Organs (including the womb if pregnant).
  • Improves Digestion.
  • Increases Lung Capacity.
  • Increases Blood Circulation.
  • Reduces Compression of the Discs in Lumbar Spine (by 35% compared to a typical seated posture).
  • Decreases risk of Disc Prolapse.
  • Relieves Back Pain.
  • Improves Blood Oxygen Levels.
  • Reduces Fatigue.
  • Improves Alertness.
  • Improves Concentration.
  • Improves Performance.

http://www.kneelingchairs.com.au

http://www.posture-chair.co.uk/

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